Decking rope

How much decking rope do I need?

March marks the start of meteorological spring.

i.e. decking season.

The perfect time of year to spruce up the garden with some new wooden decking and a rope balustrade. Which means, there’s currently one big question on everyone’s mind: How much decking rope do I need to order?

It sounds like it should be pretty easy to work out, but this actually trips many people up (even experienced landscapers!) – especially when attempting to create a rope fence with swags.

So to help you order the right amount of decking rope for the job, here’s our advice on how to measure up accurately.


3 steps to calculate the perfect amount of decking rope


Step by step how to measure up for decking rope


  1. Measure from post to post

First things first, measure the distance from the centre of one decking post to the next in centimetres (cm) – taking care to keep your tape measure as straight as possible.

Then, to create a ‘swag’ or droop in the decking rope, add an extra 3-5%.

Of course, the depth of this swag is a matter of personal preference – and may need to vary depending on the size of your rope balustrade. To help you visualise how a 3-5% swag will look, perhaps measure this out using a piece of string and lay it across the decking posts.

Your decking rope will weigh more than the string, therefore causing it to drop further – which is something to keep in mind. But overall, it’s a pretty good indication of how the rope will look. If you’d like a deeper wave, just add slightly more rope to the length. If you’d prefer a shallower drop, reduce it.

(Also consider if you need to add anything on to your measurement if you are running rope around or through poles).


  1. Multiply this length by the number of additional posts

This will calculate the total amount required, to go from one post to the next with the same swag.

To err on the side of caution and give yourself some leeway, it’s usually worth adding a little extra to the final total. After all, this can simply be cut off if it turns out to be too much. We have no interest in selling more than you need, but it really is better to have a little over than find out you’ve ordered just too little!

It’s also important to note, when exposed to water, garden decking ropes made from natural fibres are prone to shrinkage. The extent of this shrinkage varies depending on how wet the rope becomes and which natural fibre it’s made from (e.g. jute, manila etc.). But for most projects, to fully counteract this effect, we typically recommend adding an extra 10-15% to the total length.

Before cutting your decking rope to size or securing it to the posts, we also advise placing it in situ in your garden and leaving it for several days – to allow the shrinkage to occur naturally.


  1. Account for the final touches

Last but not least, don’t forget about your rope end finishes.

If you plan to secure your decking railing rope with a knot at each end, add approximately 40-50cm extra for each knot. Or, if you wish to use brass hook and eye plates (e.g. to attach the rope to the final decking post or wall), they typically take up 5cms so you can deduct that from your measurement.


Rope balustrade for decking


Got it sussed?

RopesDirect is a UK leading supplier of high-quality yet affordable decking ropes.

We offer three types of decking ropejute, manila and synthetic hemp. All of which come in a wide range of diameters (from 24mm-65mm) and are sold by the metre. Which means, it’s possible to measure up and purchase the exact amount of rope for your decking project. Zero waste required.

For fence contractors and landscapers looking to buy in bulk, we also stock jute, manila and synthetic hemp ropes in large 220m coils. Again, these come in a variety of diameters. And are both competitively priced and available for next day delivery (when ordered before 12pm).


Decking ropes available at RopesDirect


So why not grab the tape measure?

Add up the numbers and place the perfect ‘decking rope’ order today. At the bottom of the page, you’ll find a simple calculation sheet that will guide you step-by-step through the process outlined above – and hopefully help to avoid any confusion!

Further tips on how to fit decking rope and create a rope balustrade for decking can also be found throughout our website. But if you’re still struggling to do the maths – or have a question about any of the products in our decking and fencing range – you’re also welcome to contact us at any time.

Simply fill out our online enquiry form and we’ll respond as soon as possible.

And remember, if you do happen to use our garden decking rope this spring, we’d love to see the final results! Either send your photos to or tag us in your pics on social media using #ropesdirect. Happy decking season!



Decking rope calculation guide


  1. Measure from post to post

Distance between post one and two:   __________cm

Add 3-5% for swag:  __________cm

Total A: __________cm


  1. Multiply

Multiple Total A by the number of additional decking posts: __________cm

Add 10-15% if using natural ropes such as jute or manila: __________cm

Total B: __________cm


  1. Add the final touches

To Total B:

Add 40-50 cm per knot OR

Deduct 5cm per brass hook and eye fixing

Overall total: ____________ cm




Leave a Reply

You must be logged in to post a comment.